Umm...
I think I already said something like this last year when this came up, but...
Its not even for sale outside of Japan, no other country or organization has the right to tell Japan what it should and should not ban.
When this story broke ONE YEAR AGO, I remember reading a piece about it on a women's rights site. And as much as I support women's rights and well, everyone's rights for that matter... I have to disagree with the crux of their argument for banning games like Rapelay. Their argument was more or less as follows: Games like Rapelay normalize violence and will lead to increased sex crime rates.
Umm... first off... that sounds a bit like "everyone who reads porn will commit rape at some point" argument. Which turned out to be false by the way. It has been psychologically proven that most rapists aren't after the sex, they're after power.
Secondly, the game itself isn't normalizing violence. In truth, women's-rights-organization's-site-name-I-can't-remember, you are normalizing sexual violence by saying that any game is doing so. Here's why: By saying that all it takes for me, you, anybody to go out and commit rape or murder or whatever horrible crime, is one game, you are normalizing violence. By saying that, you are telling every rapist, murderer or any other kind of violent criminal, that it isn't really their fault, that every heinous act they've committed is because they were exposed to one random piece of media at some point in their lives.
So no, we shouldn't ban it. And neither should Japan, but that's their call.